This morning, the internet infrastructure company that services 8chan, Cloudflare, said the site had "repeatedly proven itself to be a cesspool of hate" and it would terminate its service as of midnight tonight Pacific Time - meaning its users will no longer be protected from cyber attacks.

Crusius killed 20 and injured dozens with a rifle in an area packed with as many as 3000 people during the busy back-to-school shopping season.

The atrocity is the third of its kind this year where a suspect is believed to have taken to 8chan in advance of an attack, including the massacre that left 51 Muslims dead in Christchurch and shooting at a synagogue in Poway, California, which left one person dead and three injured.

Disturbingly, even after the El Paso's threats turned out to be real, 8chan filled with posts referring to the alleged shooter as "our guy" and praising the number of people killed.

Others criticised his death toll or suggested he "should've done a synagogue or a mosque" instead.

"All of you limp wristed p*****s crying about how he shouldn't have done it, what have you done?" wrote one user this morning, on a thread called "Patrick is a Badass".

"Nothing. You've done nothing and you never will. Patrick is more of a man than you'll ever be. Hail our Martyrs, Hail Victory!"

WHAT IS 8CHAN?

8chan is filled with racist and anti-Semitic conspiracy theories. Almost everybody the site participates anonymously. Pretty much anything goes.

The only rule is that users should not post content that is illegal in the United States, such as child-exploitation material.

The online bulletin board was modelled another message board called 4chan. However, the founders of 4chan had the power to delete threads - meaning the more extreme "free speech" enthusiasts flocked to the less regulated forums of 8chan.

Now that the site has been linked to a number of atrocities, targeting Jews, Muslims and Mexicans, there have been calls for a crackdown on 8chan by various governments.

And, even one of the site's founders - who set out to create what he called a "free speech friendly 4chan alternative" while he was on magic mushrooms - says he wants the madness to stop.

As news of El Paso broke, 8chan founder Fredrick Brennan, who stopped working with the site's current owner last year, called for the forum to be taken offline before it leads to further violence.

"Shut the site down," Mr Brennan told The New York Times in an interview on Sunday. "It's not doing the world any good.

"It's a complete negative to everybody except the users that are there. And you know what? It's a negative to them, too. They just don't realise it."

More extreme commenters flocked to 8chan in 2014, when supporters of collection of anti-feminist computer gamers supporting a misogynistic harassment campaign known as Gamergate were booted from other forums.

Gaming is still a major discussion point on the site's messaging board - resulting in a disturbing crossover between fantasy and real-life violence.

When a mass shooting takes place, there are references to "high scores", relating to the death toll, and shooters like Brenton Tarrant used a helmet camera - which made the horrific footage look like a First Person Shooter video game.

The Poway Synagogue shooter - like Tarrant - posted a musical playlist to accompany his shooting.

A defence used by 8chan users is that a lot of what is posted on the site is not meant to be taken seriously and those who are offended don't get the joke.

However, disturbing trend noticed by Mr Brennan is how users who post and read extremist material on 8chan - which is supposed to be a joke - start to take it seriously.

"The other anonymous users are guiding what's socially acceptable, and the more and more you post on there you're being affected by what's acceptable and that changes you," he told Tortoise Media.

"Maybe you start posting Nazi memes as a joke… but you start to absorb those beliefs as your own, eventually. Anonymity makes people reveal themselves, but because there are other anonymous users - not just one person in a black box - it also changes what they reveal."

MASSIVE BLOW FOR 8CHAN

Despite Google stopping its indexing of 8chan in search results in 2015 and several governments, including New Zealand's, asking for 8chan to be taken down or regulated, the site is still available on the open web.

However, the site has been dealt a massive blow this morning as Cloudflare released a statement saying it is withdrawing its services.

"The rationale is simple: they have proven themselves to be lawless and that lawlessness has caused multiple tragic deaths," the statement reads.

"Even if 8chan may not have violated the letter of the law in refusing to moderate their hate-filled community, they have created an environment that revels in violating its spirit."

However, critics of this pushback say that if 8chan closes down, people with extreme opinions will just go somewhere else.

"If 8chan is shutdown here is what will happen: someone else will spin up a new imageboard, say 20chan or whatever. People will flock to that," Andrew Torba, the founder of Gab.ai, a far-right social media network popular with people deplatformed by Twitter told BuzzFeed. "Or someone will create an 8chan telegram channel. Or an 8chan Gab group. Or an 8chan Gab Social server hosted by someone else. Or they will go back to 4chan."

Even this morning, a thread has appeared on 8chan called "Where to go when they shut 8ch down?"

"Let's be honest, at this pace, it's just a matter of time," the thread's author wrote. "So any reccomendations? Where do you go when they close this s**t?"

CRUSIUS' SICK MANIFESTO

Just minutes before he went on a rampage on Sunday, a user understood to be Crusius posted a four-page manifesto on 8chan.

"This attack is a response to the Hispanic invasion of Texas," he wrote.

"They are the instigators, not me. I am simply defending my country from cultural and ethnic replacement brought on by an invasion."

The manifesto then outlined the suspect's political and economic "justifications" for mass murder.

His ramblings echoed those of Christchurch terrorist Brenton Tarrant decried immigration as an "assault on the European people".

"This is ethnic replacement. This is cultural replacement," he wrote. "This is racial replacement. This is WHITE GENOCIDE."

The El Paso shooting was being investigated as a possible hate crime and the suspected gunman could now face the death penalty.

Crusius was arrested without police firing any shots in El Paso - a border city has figured prominently in the immigration debate and is home to 680,000 people, most of them Latino.

Mexican officials said three Mexican nationals were among the dead and six more were wounded.

El Paso Police Chief Greg Allen said the suspect was cooperative and "forthcoming with information."

"He basically didn't hold anything back. Particular questions were asked, and he responded in the way that needed to be answered," Mr Allen said.